Shenango Inc. and an Australian partner want to more than double the output of the company's Neville Island coke plant, a $100 million project they say would create about 50 new jobs.

The new plant would produce 500,000 tons of coke annually using what company officials said is "the best and most environmentally friendly technology." The project would include a power plant.

"It will revolutionize coke making, not only in the United States but in the world," Shenango President Andrew Aloe said.

Aloe's partner is Antaeus Energy, a U.S. subsidiary of Greenfields Energy Corp. of Sydney. Shenango and Greenfields announced plans to merge in May, in a deal that would give Shenango a 7.35 percent stake in Greenfields. The companies expect to complete the deal before the end of the year.

Shenango's plant produces 360,000 tons of coke a year and employs about 200. Coke is a baked coal used as a fuel in steelmaking.

The proposal to expand it is the smaller of two coke plant proposals in the works here.

Sun Co. wants to build a $350 million to $400 million plant in Hazelwood that would produce 1.9 million tons of coke annually. The Sun plant, which also includes a cogeneration facility, would be built on the site of LTV Steel's coke plant that closed this year.

Both groups are seeking preliminary word from the county Health Department on whether permits would be issued for the plants, which would help them obtain financing for the projects.

Shenango and Antaeus "supplied more details than we got from the sketchy outline we got from LTV and Sun," said Roger Westman, director of the Health Department's air quality program.

Westman said the department will probably be able to give Shenango an answer in several weeks. A response to Sun depends on when the Philadelphia company provides information department officials have asked for, Westman said. "We do expect it in shortly," he said.

Antaeus would make coke using a process it purchased from Coal Technology Corp., a bankrupt company that had been funded by the U.S. Department of Energy. The technology converts wastes from coal processing plants.

Antaeus owns 8 to 10 million tons of coal wastes from a former U.S. Steel mine in Gary, W.Va. The wastes are contained in two ponds that cover 900 acres. Antaeus plans to separate the coal from water and other materials and send it to the Neville Island plant, where it would be formed into coke that looks like charcoal briquettes.

Greenfields Chief Executive Officer Stephen J. Barber said the process takes less than seven hours compared with the 20 to 24 hours it takes to make coke using traditional methods. Barber said building and operating a plant based on the new process would be cheaper than using traditional processes and would also reduce the problem of what to do with other coal waste piles. Antaeus estimates there are over 240 other ponds in West Virginia that contain millions of tons of coal waste.

"They're a major blight on the landscape in Western Pennsylvania and West Virginia," Barber said.

The cogeneration plant would produce about 24 megawatts of electricity. The Neville Island coke plant would consume about 4 megawatts and the other 20 would be sold. Barber said his company is negotiating with American Electric Power to build and operate the plant and sell the power.

Antaeus hopes to begin construction early next year and begin production early in 2000. Barber said Antaeus eventually wants to add another 1 million tons to the Neville Island plant's capacity.